The following report on the Temporary Barriers Project is for your information and action, as appropriate.  This report will be transmitted whenever changes occur to the operation of the barriers, and as a result of modeling and/or field monitoring of water levels in the south Delta.

STATUS AS OF:   July 3, 2009

Head of Old River (HOR) Barrier:

The spring Head of Old River rock barrier was not installed this season.  Instead a Non-Physical Barrier (NPB) or “bubble barrier” was installed.  Installation began April 7 and was completed and tested in time for the first of seven VAMP experiment fish releases that began April 22.  This experimental barrier—placed near the channel bottom and extending across the entrance to Old River—uses a combination of bubbles, lights, and sound to guide out-migrating Chinook salmon smolts away from Old River to continue their migration down the San Joaquin River.  Underwater receivers were installed to detect tagged smolts to study the effectiveness of this NPB.  Preliminary results indicated the NPB significantly improved the number of smolts staying in the SJR over a no-NPB condition.  The NPB was removed beginning late May and was completely removed as of June 4.

Agricultural Barriers (Old River near Tracy [ORT], Middle River [MR], Grant Line Canal [GLC]):

Installation of the ag barriers began May 18 with work at the MR and ORT barrier followed by the GLC barrier.  The MR barriers was completed June 19 and has the culvert flap gates tied open.  The ORT barrier was completed June 23 with flap gates also tied open.  The GLC barrier was completed June 24 with flap gates tied open and the weir center portion open.  Since then, the GLC barrier weir center was filled beginning June 30 and was completed July 1.  Next week, on July 7, DWR personnel will untie the flap gates on the MR and GLC barriers so they operate tidally.  The ORT barrier culverts will remain tied open for water quality purposes, and will be operated (tied open or closed) real time depending on water quality and water level conditions through the irrigation season.


Modeling results are attached.  Actual water levels are above the trigger levels (1.0 feet MSL at Old River and Grant Line Canal barriers, 0.3 feet MSL at Middle River barrier) particulary after the GLC barrier was closed.  Next week when flap gates are untied at the MR and GLC barriers, water levels are projected to increase well above the trigger point.

Click here to see modeling outputs



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Mark A. Holderman, P.E.
Chief, Temporary Barriers Project and Lower San Joaquin
Bay-Delta Office
California Department of Water Resources
1416 9th St., P.O. Box 942836
Sacramento, CA 94236-0001
Phone: (916) 653-7429  FAX: (916) 653-6077
Cell: (916) 601-6036 E-Mail: